Question

x(x+3)= (2x-1)(x+3)

Giải ptrình

Answer 1

\(\Leftrightarrow\left(2x-1\right)\left(x+3\right)-x\left(x+3\right)=0\)

=>(x+3)(x-1)=0

=>x=-3 hoặc x=1

Answer 2

\(\text{x(x+3)= (2x-1)(x+3)}\)

\(\Leftrightarrow x^2+3x=2x^2+6x-x-3\)

\(\Leftrightarrow x^2+3x-2x^2-6x+x+3=0\)

\(\Leftrightarrow-x^2-2x+3=0\)

\(a=-1\)

\(b=-2\)

\(c=3\)

\(\Delta=b^2-4ac=\left(-2\right)^2-4.\left(-1\right).3=-3< 0\)

Vậy \(S=\varnothing\)